Heat-conserving apparatus



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l RAYMOND N. nummer, or

EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC &MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

HEAT-CONSERVING APPARATUS.

Original application iled November 21, 1917, Serial No. 203,261. Dividedand this application led May 19, 1920. serial No. 382,653.

This invention relates to the conservation of heat in power developingsystems and has for an objectto produce a new and improved apparatus forpreventing or reducing the U loss of heat from such a system.

In power plants the feed water for boilersl orjsteam generators is oftenheated by exhaust steam from the auxiliaries; thatI is, by steamexhausted from the turbines or l engines which drive the circulatingpumps, air pumps, feed water pumps and the like.

The load on the auxiliaries is substantially constant irrespective ofthe load on the main power developing units, consequently l under someoperating conditions the amount of exhaust steam available forfeed'heating purposes may be considerably in excess of that required.For example, when the main units are operating` under light loads theamount of feed water to be heated is small,

but the steam delivered by the auxiliaries is approximately'the same asunder full 'load' conditions and consequently is in excessl of theamount required to heat the feed water 95 to the desied temperature. Asa result the excess steam is discharged to the atmosphere with theattendant heat loss to thel system.v

It is evident that it is desirable to proportion the amount of availableexhaust steam for heating feed water to the amount of feed water to beheated, so that all of the available heat in the exhaust steam will beeconomically utilized.

A more specific object of my invention is l to produce an apparatus formaintairing a balance between lthe amount of exhaust steam availablefor-feed water heating and the amount of feedwater to be heated.

A further 'object is to produce a power developing apparatus in whichthe load on the steam driven auxiliaries is varied in accordance withthe amount ofexhauststeam required for feed water heating purposes.

A further object is to produce new. and t* improved apparatus forcontrolling the delivery of steam to the feed water heater.

These and other objects are attained by means of apparatus embodying thefeatures herein described and illustrated in the drawo ingsaccompanaying and forming a part hereof.`

In the drawings7 grammatic sectional Figs. 1 and 2 are diaviews of anembodiment the n of my invention; and Fig. 3 is a diagram-- maticsectional view ofI a modification of the apparatus illustrated in Figs.1 and 2.

In Figs. 1 and 2, I show anv automatic device for controlling thedelivery of steam to an auxiliary turbine, whichexhausts to a feed-waterheater, or for controlling the-delivery of steam directly to afeed-water heater so as to proportionthe amount ofsteam to the amount offeed water for the purpose of maintaining a substantially constanttemperature ofthe feed waiter.

A feed water heater 31, of the open or direct contact type, is adaptedto receive water to be heated through an inlet port 32 and a group ofdistributing nozzles 33 located in the upper part of the heater. Exhauststeam for heating the water is conducted from the auxiliary turbine 18Iby a pipe' 22 and .enters the heater through an inlet port 34, whereitis condensed by the water falling from the nozzles 33. The heatedwater is collected in the bottom of theV heater and may be drawn ott'through a conduit 35. An atmospheric 'relief valvel 36 is provided inthe top of the heater forpreventing the building up of pressure in theheater. This valve opens outwardly onlv and is merely a safety valve.

As shown, the heater 31 is connected with an .air pump 37 by means o f aconduit 38.

A branch pipe 39 transmits the pressure existingin the conduit 38 to adiaphragm .40. which controls a valve 41 in the steam line 42. As shown,the diaphragm is exposed on one side to the pressure ofl the iuid in theconduit 38, and on the other side to atmospheric pressure. The steamline 42 delivers actuating steam to the auxiliaries to be subsequentlyemployed in the heater, as

.illustrated diagrammatically) in Fig. 1, or

else directly to the heater, as may be seen from Fig. 2. It is desirableto maintain a feed water temperature of say 212 F.

Vith the water in the heater 31 at this temperature the air pump 37 isincapable of reducing the pressure inthe heater below atmosphericpressure because the water vaporizes so rapidly that the formation of avacuum is prevented. In other words, the

pressure in the heater cannot be reduced below the pressurecorrespondingto the va- -porizing temperature of the water in theheater. If this temperature drops, due to a more or less completefailure of the steam lsupply or for any reason, then the pressure in theheater, the conduit 38 and the pipe 39 drops accordingly. The pressureof the.l atmosphere actingon the diaphragm 40 opens the valve 41, admitsmore steam to the auxiliaries or to the heater and thereby augments thesupply of steam to the heater sufficiently to reestablish a feed watertemperature of substantially 212 F.f i

With the air pump 37 operating, any decrease in temperature` of thewater will cause v a corresponding decrease in pressure and the 1IL Inaddition to the apparatus previously described, I have provided a smallauxiliary condenser 43 in the conduit 38 connecting the heater 31" withthe air pump, and a small centrifugal pump 44 for withdrawing water fromthe heater and for delivering it to the auxiliary condenser-43 to beemployed as cooling water.

Under some conditions, the temperature of the water in the heater 3l mayfall too low; for example because of a sudden' change in temperature orquantity of water supplied to the heater. With the apparatus illustratedin Figs. 1 and 2, an objectionable vacuum might result in the linesupplying steam to the heater. With the apparatus illustrated in Fig. 3,the vacuum would exist only in the small auxiliary condenser 43, whichis preferably located above the heater 31 so that it will not be floodedunder high vacuum. The temperature of the water in the auxiliarycondenser 43 is substantially the same as the temperature in the heater31', consequently the control of the steam supply to t-he auxiliaries isthe same as in the apparatus illustrated in Figs. 1 and 2 with the addedadvantage that only the auxiliary condenser 43 need be subjected topressures less than atmospheric.

W'hile I have shown my invention in two forms, it will be obvious 'tothose skilled in the art that it is not so limited but is'susceptible tovarious other changes 'and modifications without departing from thespirit, and I desire, therefore, that only such limitations shall beplaced thereupon as are imposed by the prior art or as'are specificallyset forth in the appended claims.

Vhat I claim is:

l. The combination of a 'feed-water heater, a water-inlet meanstherefor, a steam-inlet means, a feed-water discharge means,airdischarge means for said heater including a pump, and meansresponsive to pressure in said air-discharge means to control theadmission of steam to said heater.

2. In a heat conserving apparatus, a feed water heater, means fordelivering steam to the heater, means for maintaining a pressure withinthe heater corresponding to the boiling temperature of the water in theheater, and means responsive to variations in said pressure forcontrolling the delivery of steam to the heater.

3. In power-plant apparatus, the combination of a feed-water heater,exhausting means for the heater for maintaining the pressure therein atthe vapor pressure corresponding to the temperature of the water, meansfor supplying steam to the heater, and controlling means for the supplymeans responsive to the heater pressure. to control the amount of steamsupplied to the heater.

4. In power-plant apparatus, the combination of an open or contactheater, means connected to the heater above the Water level forexhausting air therefrom, a conduit for supplying steam to the heater, avalve in the conduit, and a pressure-responsive device subject to theheater pressure and connected to said valve.

5. In power-plant apparatus, the combination of an open or contactfeed-water heater, an air pump connected to the heater above the levelof water therein, a conduit for supplying steam to the heater, a valvein the conduit, and means subject to the heater pressure for moving thevalve in an opening direction upon a decrease of heater pressure and formoving the valve in a closing direction upon an increase in heaterpressure.

6. In power-plant apparatus, the combination of a feed-water heatermeans for ad- 'mitting water and steam to the heater exhausting meansfor the heater, and means responsive to the vapor pressure of the waterin the heater for controlling the admission of steam to the heater.

7. In power-plant apparatus, the combination of a feed-Water heater, apower developing unit, means for admitting water to the heater, meansfor admitting steam to the power-developing unit and for conducting theexhaust thereof to the heater, means f r maintaining in the heater apressure substantially equal to the vapor pressure corresponding to thetemperature of the water within the heater, and means responsive to thevapor pressure of the water in the heater for controlling the admissionof steam to the heater.

e In testimony whereof, I have hereunto subscribed my name this 15th dayof May,

RAYMOND N. EHRHART.

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